Association between perfluoroalkyl substances and thyroid stimulating hormone among pregnant women: a cross-sectional study

BACKGROUND

Perfluoroalkyl substances (PFASs) are a group of highly persistent chemicals that are widespread contaminants in wildlife and humans. Exposure to PFAS affects thyroid homeostasis in experimental animals and possibly in humans. The objective of this study was to examine the association between plasma concentrations of PFASs and thyroid stimulating hormone (TSH) among pregnant women.

METHODS

A total of 903 pregnant women who enrolled in the Norwegian Mother and Child Cohort Study from 2003 to 2004 were studied. Concentrations of thirteen PFASs and TSH were measured in plasma samples collected around the 18th week of gestation. Linear regression models were used to evaluate associations between PFASs and TSH.

RESULTS

Among the thirteen PFASs, seven were detected in more than 60% of samples and perfluorooctane sulfonate (PFOS) had the highest concentrations (median, 12.8 ng/mL; inter-quartile range [IQR], 10.1 -16.5 ng/mL). The median TSH concentration was 3.5 (IQR, 2.4 - 4.8) μIU/mL. Pregnant women with higher PFOS had higher TSH levels. After adjustment, with each 1 ng/mL increase in PFOS concentration, there was a 0.8% (95% confidence interval: 0.1%, 1.6%) rise in TSH. The odds ratio of having an abnormally high TSH, however, was not increased, and other PFASs were unrelated to TSH.

CONCLUSIONS

Our results suggest an association between PFOS and TSH in pregnant women that is small and may be of no clinical significance.

Remission, continuation and incidence of eating disorders during early pregnancy: a validation study in a population-based birth cohort

BACKGROUND

We internally validated previously published rates of remission, continuation and incidence of broadly defined eating disorders during pregnancy in the Norwegian Mother and Child Cohort (MoBa) at the Norwegian Institute of Public Health.

METHOD

A total of 77 267 pregnant women enrolled at 17 weeks gestation between 2001 and 2009 were split into a training sample (n = 41 243) from the version 2 dataset and a validation sample (n = 36 024) from the version 5 dataset who were not in the original study. Internal validation of original rate models involved fitting a calibration model to compare model parameters between the two samples and bootstrap estimates of bias in the entire version 5 dataset.

RESULTS

Remission, continuation and incidence estimates remained stable. Pre-pregnancy prevalence estimates in the validation sample were: anorexia nervosa (AN; 0.1%), bulimia nervosa (BN; 1.0%), binge eating disorder (BED; 3.3%) and eating disorder not otherwise specified-purging disorder (EDNOS-P; 0.1%). In early pregnancy, estimates were: BN (0.2%), BED (4.8%) and EDNOS-P (<0.01%). Incident BN and EDNOS-P during pregnancy were rare. The highest rates were for full or partial remission for BN and EDNOS-P and continuation for BED.

CONCLUSIONS

We validated previously estimated rates of remission, continuation and incidence of eating disorders during pregnancy. Eating disorders, especially BED, during pregnancy were relatively common, occurring in nearly one in every 20 women. Pregnancy was a window of remission from BN but a window of vulnerability for BED. Training to detect eating disorders by obstetricians/gynecologists and interventions to enhance pregnancy and neonatal outcomes warrant attention.

Course and predictors of maternal eating disorders in the postpartum period

OBJECTIVE

To investigate course and predictors of eating disorders in the postpartum period.

METHOD

A total of 77,807 women, participating in the Norwegian Mother and Child Cohort Study (MoBa), completed questionnaires during pregnancy including items covering DSM-IV criteria for prepregnancy anorexia nervosa (AN), bulimia nervosa (BN), eating disorder not otherwise specified (EDNOS-P), and binge eating disorder (BED). Additional questionnaires were completed at 18 and 36 months postpartum.

RESULTS

Proportions of women remitting at 18 months and 36 months postpartum were 50% and 59% for AN, 39% and 30% for BN, 46% and 57% for EDNOS-P, and 45% and 42% for BED, respectively. However, disordered eating persisted in a substantial proportion of women meeting criteria for either full or subthreshold eating disorders. BN during pregnancy increased the risk for continuation of BN. BMI and psychological distress were significantly associated with course of BED.

DISCUSSION

This is the first large-scale population-based study on course of eating disorders in the postpartum period. The results indicated that disordered eating persists in a substantial proportion of women with prepregnancy eating disorders. Health care professionals working with women in this phase of life need to pay specific attention to eating disorder symptoms and behaviors.

Attention problems and language development in preterm low-birth-weight children: cross-lagged relations from 18 to 36 months

BACKGROUND

Research has highlighted a series of persistent deficits in cognitive ability in preterm low-birth-weight children. Language and attention problems are among these deficits, although the nature of the relation between attention and language in early development is not well known. This study represents a preliminary attempt to shed light on the relations between attention problems and language development in preterm low-birth-weight children.

METHODS

The aim of this study was to analyse reciprocal influences between language and attention problems from 18 to 36 months. We used maternal reports on attention problems and language ability referring to a sample of 1288 premature low-birth-weight infants, collected as part of the Norwegian Mother and Child Cohort Study (MoBa). A sample of children born full-term was used as the control group (N = 37010). Cross-lagged panel analyses were carried out to study reciprocal influences between attention problems and language.

RESULTS

Language ability at 18 months did not significantly predict attention problems at 36 months, adjusting for attention problems at 18 months. Attention problems at 18 months significantly predicted changes in language ability from 18 to 36 months, pointing to a precursor role of attention in relation to language in children born preterm. Gender, age corrected for prematurity, and mother's education emerged as important covariates.

CONCLUSIONS

Preliminary evidence was found for a precursor role of early attention problems in relation to language in prematurity. This finding can contribute to a better understanding of the developmental pathways of attention and language and lead to better management of unfavourable outcomes associated with co-morbid attention and language difficulties.